Refractive index detector and liquid chromatograph

Abstract

An embodiment of a refractive index detector includes a sample cell, a reference cell, a measurement section, a liquid inlet port, liquid outlet sections, and a switching mechanism. The inlet port leads to a sample cell inlet. A first outlet port and a second outlet port are for discharging a liquid. The switching mechanism includes a reference liquid supply mode for forming a channel for connecting a reference cell outlet to one of the first outlet port and the second outlet port while connecting a sample cell outlet to a reference cell inlet, and an analysis mode for forming a channel for connecting the sample cell outlet to one of the first outlet port and the second outlet port while sealing the reference cell outlet.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention relates to a refractive index detector for detecting a refractive index difference between a sample cell through which a sample flows and a reference cell containing a reference liquid, based on the behavior of light which has passed through the sample cell and the reference cell, and for measuring the concentration of a sample flowing through the sample cell based on the refractive index difference, and a liquid chromatograph that uses the refractive index detector.[0003]2. Description of the Related Art[0004]A refractive index detector is used by a liquid chromatograph as a detector for detecting a sample component separated by an analytical column. The refractive index detector includes a sample cell and a reference cell that are provided being separated from each other by a partition wall, and causes a sample solution to flow in the sample cell in a state where a reference liquid (a solvent not...

AI Technical Summary

Benefits of technology

[0009]According to such a structure, the refractive index detector of the present invention may selectively discharge, from either the first outlet port or the second outlet port, a liquid which has passed through the sample cell, or a liquid which has passed through the sample cell and the reference cell. Accordingly, if a recycle channel leading to the original solvent container is connected to either the first outlet port or the second outlet port, a solvent may be returned to the solvent container as necessary without using a separate switching valve. Since there is no need to use an external switching valve, the cost and the installation area are not increased, and control is not complicated. Since an external switching valve is not used, even if a detector such as a mass spectrometer is provided at a later stage of the refractive index detector, the dead volume between the refractive index detector and the detector at the later stage side is small, and influence of diffusion of a sample on analysis may be made small.

[0011]According to such a structure, the liquid chromatograph according to the present invention may return, as necessary, a solvent which has passed through the refractive index detector to the solvent container and may reuse the solvent, without increasing the cost and the installation area.

Problems solved by technology

However, in cases such as where using an expensive solvent, a solvent, in the solvent to be discharged from the outlet port, not containing a sample is desirably returned to the original solvent container to be reused.

Then, the switching valve inside the refractive index detector and the switching valve that is separately provided on the later stage side are simultaneously controlled, and thus, control is complicated.

Moreover, since an external switching valve has to be provided, there are problems that the cost and the installation area are increased.

Furthermore, when an external switching valve is provided, a dead volume is increased by this amount, and there is a problem that, in the case where a detector such as a mass spectrometer is connected immediately after the switching valve, the sample component is diffused, thereby affecting the analysis result.

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